Stars of Doctor Who, Little Britain, The Vicar of Dibley and more hit shows are taking part in a star-studded fundraising telethon on BBC One.
Children in Need and Comic Relief have joined forces for the first time to stage The Big Night In.
It is celebrating key workers and raising money for people who have been affected by the coronavirus crisis.
Ten Doctor Who actors from the past 50 years have recorded a thank you message to real doctors and other NHS staff.
Those taking part range from Tom Baker, who played the role between 1974-81, to current Doctor Jodie Whittaker and Jo Martin, who appeared as an alternative incarnation of the character in two episodes earlier this year.
Matt Lucas and David Walliams are doing Little Britain on TV for the first time in a decade.
Dawn French is reviving The Vicar of Dibley, while Peter Kay is unveiling a new video for (Is This The Way To) Amarillo.
Catherine Tate is bringing back schoolgirl Lauren – who is struggling with being remotely educated by her teacher, played by David Tennant.
The show aims to raise millions of pounds for causes around the UK supported by Comic Relief and Children In Need. The government has pledged to match all public donations, with a minimum of £20m.
The programme is also celebrating “the acts of kindness, humour and the spirit of hope and resilience that is keeping the nation going”.
It includes the unveiling of a home-made video for a charity single featuring stars like Dua Lipa, Chris Martin and Rita Ora.
They – along with the likes of Ellie Goulding, Jess Glynne, Paloma Faith and Rag ‘N’ Bone Man – have recorded a cover of Foo Fighters’ 2003 track Times Like These.
Gary Barlow, Steve Coogan, Rob Brydon, Jack Whitehall, Romesh Ranganathan, Miranda Hart and the cast of People Just Do Nothing are among the others appearing on the show.
And the Strictly Come Dancing professionals have come up with a new routine for people to learn at home.
The programme is hosted by Matt Baker, Zoe Ball, Sir Lenny Henry, Paddy McGuinness and Davina McCall.
“It’s so exciting to actually be able to do something positive… especially bringing Comic Relief and Children In Need together for one night only,” McCall told BBC Radio 5 Live on Wednesday.
Sir Lenny told BBC Breakfast on Saturday the aim of the night was to let “the key workers and the care workers know that we really respect what they’re doing”, he said.
Speaking about the fundraising, he added: “A lot of the projects that we support have come to us and said that they’re really struggling in this time. They need our help.”